Allow use of "_" character for a Property

[Roger Rines]

When naming a control, I like to append a control shortcut name to the property name so that it is clear what the name is about.  For example, a form's EXIT button would be named: "Exit_BTN".  I'm doing this now, but without the underscore character: "ExitBTN".  While this is working, it slows the code reading down to the point where I often miss what I'm looking for on the first pass until I remind myself I won't see the "_" character.